20152321666 has 8 divisors (see below), whose sum is σ = 30740829840. Its totient is φ = 9905378388.

The previous prime is 20152321661. The next prime is 20152321667. The reversal of 20152321666 is 66612325102.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×20152321666² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20152321661) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 85391076 + ... + 85391311.

It is an arithmetic number, because the mean of its divisors is an integer number (3842603730).

Almost surely, 2^20152321666 is an apocalyptic number.

20152321666 is a deficient number, since it is larger than the sum of its proper divisors (10588508174).

20152321666 is a wasteful number, since it uses less digits than its factorization.

20152321666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 170782448.

The product of its (nonzero) digits is 25920, while the sum is 34.

Adding to 20152321666 its reverse (66612325102), we get a palindrome (86764646768).

The spelling of 20152321666 in words is "twenty billion, one hundred fifty-two million, three hundred twenty-one thousand, six hundred sixty-six".